The task of replacing seven-time MotoGP world champion Valentino Rossi at Ducati has been handed to his fellow Italian Andrea Dovizioso.

Legendary rider Rossi will return to former team Yamaha Factory Racing on a two-year deal at the start of the 2013 season, a move which will see him reunited with fellow title winner and rival Jorge Lorenzo.

Dovizioso, currently riding for the Monster Yamaha Tech 3 satellite outfit, is fourth in the standings after 11 rounds of the 2012 season, 46 points ahead of Rossi.

The 26-year-old will spend his sixth season in the elite division of motorbike racing at the Italian team, alongside American 2006 champion Nicky Hayden.

"It is with great pleasure that I welcome Andrea, as we marshal our best efforts in confronting the MotoGP World Championship," Ducati president Gabriele Del Torchio said of the 26-year-old on MotoGP's official website.

"Along with Nicky Hayden, with whom we have renewed a working agreement, we are confident that we will be able to proceed with our development program, to compete, and to obtain the results and rewards that will repay our efforts and the faith that our partners, sponsors and fans have never failed to demonstrate."

Dovizioso finished the 2011 championship in third position and will hope for better results at Ducati than Rossi achieved -- the 33-year-old has recorded just two podium finishes in 28 races.

Ducati will be without Hayden for this weekend's Czech Grand Prix after he picked up a hand injury during a qualifying crash at the last race in Indianapolis, meaning Rossi will be the team's sole rider at Brno.

Reigning world champion Casey Stoner, third in the 2012 riders' standings, is a doubt to race this weekend after a crash in the U.S. left the Australian with a fractured bone in his right ankle and torn ligaments.

Despite picking up the injuries in qualifying ahead of the race, Stoner was still able to compete in the grand prix and register a fourth-place finish.

His Honda teammate Dani Pedrosa took the checkered flag, but the Spanish rider is still second behind Lorenzo in the world championship with seven races remaining.

"I'm not feeling too optimistic for Brno after a tough weekend in Indy," explained Stoner. "The crash in qualifying last week has left me with a serious problem in my ankle.

"We were fortunate that Indy was a left-hand circuit so a lot of the weight was off it, but we still had changes of direction, which hurt a lot.

"In Brno there are many changes in direction and a lot of right-hand corners, so there will be a lot of weight on my ankle and it's going to be very difficult.

"It's a shame as Brno is a circuit that I usually enjoy due to its fast and flowing nature, so I'll be resting as much as possible this week and wait to see how we feel when we get on track on Friday."